1. Field of the Invention
The present invention pertains to a multi-clutch arrangement, especially a dual clutch for motor vehicles, comprising a first clutch area with a first pressure plate arrangement, with a first opposing support arrangement, and with a first clutch disk arrangement, which can be clamped between the first pressure plate arrangement and the first opposing support arrangement to transmit torque via the first clutch area; and a second clutch area with a second pressure plate arrangement, with a second opposing support arrangement, and with a second clutch disk arrangement, which can be clamped between the second pressure plate arrangement and the second opposing support arrangement to transmit torque via the second clutch area.
2. Description of the Related Art
A multi-clutch arrangement of this type, designed as a dual clutch, is known from EP 0 185 176 A1. In this clutch, the two clutch areas are arranged in sequence in the direction of the axis of rotation of the overall system. A housing arrangement is provided at one axial end of the dual clutch for connection to a drive shaft, whereas two clutch-release systems, which can be activated independently of each other, act on the other axial end of the dual clutch.
Dual clutches of this type are often used in conjunction with very high-torque drive trains and in conjunction with so-called load-switching transmissions. Very strong torque-induced vibrations are excited in various speed ranges in these types of drive systems, such as direct-injection diesel engines, and unless these vibrations are damped, they are transmitted to the following part of the drive train and lead not only to considerable stress on the various components of the drive train but also to an unpleasant driving sensation.
The task of the present invention is to provide a multi-clutch arrangement, especially a dual clutch for motor vehicles, in which the disadvantages arising through the excessive excitation of vibrations are at least decreased.
According to the present invention, a torsional vibration damper arrangement is assigned to at least one of the clutch areas, andxe2x80x94relative to the axis of rotationxe2x80x94the torsional vibration damper arrangement is installed at least partially in the axial area of the first clutch area and/or of the second clutch area.
By providing at least one of the clutch areas with a torsional vibration damper arrangement, it can be ensured that a damping function is available especially in the speed ranges which are critical with respect to the excitation of vibrations. The design according to the invention also ensures a compact design, in which various systems in the clutch area on the one hand and various systems of the torsional vibration damper arrangement on the other hand are positioned so that they overlap each other in the axial direction. This is especially important for dual clutches or multi-clutch arrangements, because there are already several clutch areas arranged in a row in the axial direction in these devices and thus a comparatively large amount of space is occupied. In addition to the goal of providing a significant increase in driving comfort, this compactness of design is an essential aspect which must be considered when systems of this type are to be integrated into passenger vehicles.
To achieve an even further reduction in the amount of space required by allowing certain parts to perform double duty and/or by combining certain functions, it is proposed that at least one of the opposing support arrangements forms part of the torsional vibration-damper arrangement. For example, it is possible for the torsional vibration-damper arrangement to comprise a central disk element, which has a cover disk element on each side. These cover disk elements are rigidly connected to each other and are connected to the central disk element by a damper element arrangement for the transmission of torque, where at least one of the cover disk elements forms at least part of the opposing support arrangement of one of the clutch areas. To be able to achieve optimum space savings here while still providing the desired damping function, it is proposed that the two clutch areas with their opposing support arrangements be positioned so that they are facing each other and so that each of the opposing support arrangements forms at least part of one of the cover disk elements.
When individual parts are called upon to serve more than one function as indicated above, it must be ensured that each of the individual functions is still filly performed. It is therefore proposed that the cover disk elements be equipped with support areas designed to cooperate with the damper element arrangement and that, in the case of at least one of the cover disk elements, the support areas be provided radiallyxe2x80x94relative to an axis of rotationxe2x80x94inside a friction surface area provided on the cover disk element for frictional contact with a clutch disk arrangement.
Another contribution to compactness of design is achieved by providing actuating force-transmitting elements which extend through the central disk element to act on at least one of the pressure plate arrangements for the execution of clutch-engaging and disengaging operations, and by allowing at least some of these actuating force-transmitting elements to cooperate with the central disk element to limit the rotational angle of the torsional vibration damping arrangement. It is even more advantageous here for the actuating force-transmitting elements which cooperate with the central disk element to limit the rotational angle of the torsional vibration damper arrangement to pass through the opposing support arrangement assigned to the minimum of one pressure plate arrangement essentially without any play in the circumferential direction. In this way, it is also ensured simultaneously that the pressure plate arrangement and the opposing support arrangement provided for it are held essentially without freedom of rotation with respect to each other. The actuating force-transmitting elements thus also perform an additional function.
Depending on the drive unit or on the design of the drive system, it is possible for various speed or frequency ranges which are critical with respect to the excitation of rotational vibrations to be present. Because is often difficult for a single torsional vibration damper arrangement to handle several different excitation-critical ranges, it is proposed that at least one additional torsional vibration damper arrangement be provided. With respect to the direction in which the forces are transmitted, this can be installed in series with the previously discussed torsional vibration damper arrangement. It can, for example, be installed in the area of a clutch disk arrangement. According to another design variant, which can be realized alternatively or additionally, the minimum of one additional torsional vibration damper arrangement is designed to be connected on the input side to a drive element and is connected on the output side to the central disk element of the torsional vibration damper arrangement.
It is also obvious that, alternatively or in addition, the minimum of one additional torsional vibration damper arrangement could be installed so that, in terms of the transmission of forces, it is in parallel with the previously discussed torsional vibration damper arrangement. This can be accomplished by connecting the minimum of one additional torsional vibration damper arrangement on the input side to a drive element and also to an input area of the first torsional vibration damper arrangement, whereas, on the output side, it is connected to an output area of the torsional vibration damper arrangement.
The multi-clutch arrangement according to the invention can also be designed in such a way that, in the area of a housing arrangement of the clutch, the clutch arrangement is supported in the axial direction and/or in the radial direction with respect to a stationary assembly, preferably the transmission housing. It is possible to produce a complete force-feedback circuit within the clutch arrangement upon exertion of an actuating force and thus to relieve the bearing of the drive shaft of stress by, for example, supporting an input area of the torsional vibration damper arrangement in the axial and/or in the radial direction by way of a bearing arrangement on an output area of the torsional vibration damper arrangement.
So that the vibrational damping characteristic of the torsional vibration damper arrangement can be adjusted, the arrangement can also have a frictional damping device. The friction device is preferably located radially outside a damper element arrangement of the torsional vibration damper arrangement.
According to one of the other aspects exploiting the principles of the present invention, an easy-to-construct embodiment is obtained by providing the torsional vibration damper arrangement with a primary side, which is connected to the drive element, and a secondary side, which is connected to the opposing support arrangement of the multi-clutch arrangement, the secondary side being connected to the primary side for the purpose of transmitting torque by a damper element arrangement.
To arrive in this case at the most compact possible design in the axial direction, it is proposed that the secondary side and/or the damper element arrangement axially overlap a pressure plate arrangement of one of the clutch areas. For this purpose, the damper element arrangement is preferably located essentially radially inside the pressure plate arrangement of the one clutch area.
So that it is possible to compensate for an offset between the two shaft areas to be connected by way of this system, to compensate for a tilt between these two shaft areas when the torsional vibration damper arrangement and the multi-clutch arrangement are staggered axially in the manner previously described, or to compensate for the wobbling of the drive shaft with respect to the transmission input shaft or shafts which may occur especially in the case of high-torque, direct-injection spark-ignition and diesel engines, it is proposed that the secondary side of the torsional vibration damper arrangement be connected with axial elasticity to the opposing support arrangement. As a result of this axially elastic connection, it is possible to disconnect the torsional vibration damper arrangement from the opposing support arrangement with respect to wobbling.
It is also possible for the multi-clutch arrangement to be is supported at least axially with respect to the drive element by the secondary side of the torsional vibration damper arrangement.
Other objects and features of the present invention will bercome apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims. It should be further understood that the drawings are not necessarily drawn to scale and that, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein.